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1、窒壁墨型查蘭堡主蘭竺笙苧一一——Theteststudyofhardx-rayofphasecontrastimagingAbstractBackgroundsandobjectiveSincethediscoveryofx。raysbyConradRontgenin1895,almostallthepracticalusesofradiographyforhumanimaginghavebeenbasedonX.rayabsorbfioncontrastandopticgeometric.Thisabsorbtioncontrastimagingutilizedthehighpene
2、trabilityofX—ray,whenitpassthroughanobjectalonedifferentpathswillbedifferentiallyabsorbedandtheintensitypattemoftheemergingbeamrecordsthedistributionofabsorbingmaterialswithinthesample.thismethedcangivethematerialsinnerinformationwhichotherscannotsupply.eventhrough,asthesofttissuewhichbasedonlig
3、htelementsbecausethesofttissueonlyhavelittleabsorbtionornoabsorbtionorhavelittlediffrentialinabsorbtionSOitonlyinvestigatedfewinformationwithinsofttissue.in1965,doctorBonse.Ufind,forlightelements,e.g.carbon,hydrogen,oxygen,nitrogen.,thecrosssectionofthephaseshiftis1000timeslargerthanthatofabsorb
4、tion,itmeansthesensitivityofthismethodisaboutathousandtimeslargerthantheabsorbtioncontrast,indicatingthepossibilityofobtainingequivalentinformationaboutanobject,withaconsiderablyreducedabsorbeddose.a(chǎn)scomparedwithabsorbtionimaging.thistechniqueshaveadvantagestoimagethe,internalstructureofthicksam
5、ple,atthesametimeitcallimprovetheresolutiongreatlyandreachseveralmicron.wimtheadventofsynchrotronradiationfacility,thisphasecontrastimagingtechniquesgointorealityandgainedhighattation.a(chǎn)tpresent,thistechniquesaboutphasecontrastimaginghaveimprovedgreatlyandphsecontrast—CTisavailable.inOLlrcountryi
6、tisinitial,inthisarticleweintroduceourtestthatperfomedinBeijingsynchrotronradiationfacility(BSRF),severalbiologicalobjectwereusedinthistestandobtainedphasecontrastimaging.thequality&thisimagingwereanalysisedandcomparedwiththatabsorbtionimagingSOthattofindthedifferencebetweenthattwoimaging.Method
7、sweperformedsomeexperimentstoobtainphasecontrastimagingsand7安徽匿科大學(xué)碩士學(xué)位論文absorbtioncontrastimagingsofseveraldifferentbiologicalobjectsinBeijingsynchrotronradiationfacility(BSRF4WIA).theobjectincludesmallaquariumgoldfish,phyma